A New Genus of Marine Scuticociliate (Protozoa, Ciliophora) from Northern China, with a Brief Note on Its Phylogenetic Position Inferred from Small Subunit Ribosomal DNA Sequence Data

ABSTRACT. The morphology, infraciliature, and silverline system of a new marine scuticociliate, Wilbertia typica n. g., n. sp., collected from coastal waters off northern China, were investigated. The new genus Wilbertia is characterized as follows: sculptured and dorso-ventrally flattened body; dominant buccal field that is almost completely surrounded by the paroral membrane; three apically positioned long membranelles, arranged in parallel; membranelle (M)1 and M2 prominent, M3 small; reticulate silverline system. The type species W. typica n. sp. is defined by having a conspicuous anterior beak-like protrusion; five to eight caudal cilia; M1 four-rowed, M2 two-rowed; M3, single-rowed, bipartite; 15 or 16 somatic kineties; contractile vacuole positioned just posterior to the buccal field; globular macronucleus. The small subunit ribosomal DNA sequence of W. typica is 98.5% similar to the similar morphotype, Eurystomatella sinica . Phylogenetic analyses indicate that Wilbertia groups with Eurystomatella sinica forming a branch that diverges at a deep level from all other pleuronematid scuticociliates. The molecular and morphological data indicate that Wilbertia should be placed within the family Eurystomatidae, which is closely related to the well-known Cyclidiidae.     

Morphological and Molecular Redefinition of Euplotes platystoma Dragesco & Dragesco‐Kernéis, 1986 and Aspidisca lynceus (Müller,1773) Ehrenberg, 1859, with Reconsideration of a “Well‐known” Euplotes Ciliate,Euplotes harpa Stein, 1859 (Ciliophora,Euplotida)

We documented the morphology, infraciliature, silverline system, and molecular data of two euplotid species isolated from China, including two populations of the poorly known Euplotes platystoma Dragesco & Dragesco‐Kernéis, 1986 and the previously well described Aspidisca lynceus (Müller, 1773 ) Ehrenberg, 1830. Based on the information available, an improved diagnosis of Euplotes platystoma is given, including: a narrow adoral zone with 44–68 membranelles, 10 frontoventral, 5 transverse, 2 left marginal and 2 caudal cirri, 11–13 dorsal kineties with 17–25 dikinetids in the mid‐dorsal row, and dorsal silverline system of the double‐eurystomus type. The Chinese population of Aspidisca lynceus closely resembles previously described populations. Phylogenetic analyses inferred from SSU rDNA sequences show that E. platystoma is closely related with E. neapolitanus, and the internal position of A. lynceus within this genus is still not robust. A reconsideration of the “well‐known” Euplotes harpa and a comparison of all SSU rDNA sequences of E. harpa in GenBank are provided. We speculate that the sequences available from GenBank under the name of E. harpa are very likely from misidentified materials, that is, the identity of the species currently associated with the SSU rDNA of this “well‐known” form in molecular databases requires further confirmation.     

SSU rRNA GENE PHYLOGENY OF MORPHOSPECIES AFFILIATED TO THE BIOASSAY ALGA “SELENASTRUM CAPRICORNUTUM” RECOVERED THE POLYPHYLETIC ORIGIN OF CRESCENT‐SHAPED CHLOROPHYTA1

The generic concept of coccoid green algae exhibiting a crescent‐shaped morphotype is evaluated using SSU rRNA gene sequence analyses and light and electron microscopical observations. These common chlorophytes evolved polyphyletically in 10 different clades of the Chlorophyceae and three clades of the Trebouxiophyceae. Six clades are assigned to known genera of Selenastraceae: Kirchneriella, Nephrochlamys, Raphidocelis, Rhombocystis, Selenastrum, and Tetranephris. Four other clades, named following their present genus designation as Ankistrodesmus‐like I and II and Monoraphidium‐like I and II, require further investigation. One crescent‐shaped morphotype, which evolved within the Trebouxiophyceae, is designated as Neocystis mucosa sp. nov. The other two lineages containing trebouxiophycean algae with this morphotype are the Elliptochloris and the Watanabea clades. The taxonomic placement of the widely used bioassay strain “Selenastrum capricornutum” NIVA‐CHL 1 in the genus Raphidocelis (species name Raphidocelis subcapitata) is indicated by molecular data.     

Pyramidodinium spinulosum sp. nov. (Dinophyceae), a sand‐dwelling non‐motile dinoflagellate from the seafloor (36 m deep) off Mageshima Island,Kagoshima, Japan

A new species of benthic marine dinoflagellate, Pyramidodinium spinulosum Horiguchi, Moriya, Pinto & Terada is described from the deep (36 m) seafloor off Mageshima Island, Kagoshima Prefecture, Japan in the subtropical region of the northwest Pacific. The life cycle of the dinoflagellate consists of a dominant, attached, dome‐shaped, vegetative form and short‐lasting, motile cell. Asexual reproduction takes place by the formation of two motile cells within each non‐motile cell. The released motile cells swim only for a short period and transform directly into the dome‐shaped vegetative form. The duration of the cell cycle varies and can be extremely long, ranging 5–38 days under culture conditions. The non‐motile cell is enclosed by a cell wall and its surface is covered with many (80 – 130) spines of various length. The dinoflagellate is photosynthetic and contains many (more than 50) discoidal chloroplasts. Phylogenetic analysis reveals that the dinoflagellate is closely related to the type species of the genus Pyramidodinium, P. atrofuscum which also possesses a dominant, attached, non‐motile form. However, P. spinulosum can be clearly distinguished from P. atrofuscum by the cell shape (dome‐shaped vs. pyramid‐shaped) and surface ornamentation (spines vs. wart‐like processes) of the non‐motile form. Based on these morphological differences together with molecular evidence, it was concluded that this organism from a deep water sand sample should be described as a second species of the genus Pyramidodinium, P. spinulosum.     

Genetic barcoding of dark‐spored myxomycetes (Amoebozoa)—Identification,evaluation and application of a sequence similarity threshold for species differentiation in NGS studies

Unicellular, eukaryotic organisms (protists) play a key role in soil food webs as major predators of microorganisms. However, due to the polyphyletic nature of protists, no single universal barcode can be established for this group, and the structure of many protistean communities remains unresolved. Plasmodial slime moulds (Myxogastria or Myxomycetes) stand out among protists by their formation of fruit bodies, which allow for a morphological species concept. By Sanger sequencing of a large collection of morphospecies, this study presents the largest database to date of dark‐spored myxomycetes and evaluate a partial 18S SSU gene marker for species annotation. We identify and discuss the use of an intraspecific sequence similarity threshold of 99.1% for species differentiation (OTU picking) in environmental PCR studies (ePCR) and estimate a hidden diversity of putative species, exceeding those of described morphospecies by 99%. When applying the identified threshold to an ePCR data set (including sequences from both NGS and cloning), we find 64 OTUs of which 21.9% had a direct match (>99.1% similarity) to the database and the remaining had on average 90.2 ± 0.8% similarity to their best match, thus thought to represent undiscovered diversity of dark‐spored myxomycetes.     

“Lucy” (A.L. 288‐1) had five sacral vertebrae

A “long‐backed” scenario of hominin vertebral evolution posits that early hominins possessed six lumbar vertebrae coupled with a high frequency of four sacral vertebrae (7:12‐13:6:4), a configuration acquired from a hominin‐panin last common ancestor (PLCA) having a vertebral formula of 7:13:6‐7:4. One founding line of evidence for this hypothesis is the recent assertion that the “Lucy” sacrum (A.L. 288‐1an, Australopithecus afarensis) consists of four sacral vertebrae and a partially‐fused first coccygeal vertebra (Co1), rather than five sacral vertebrae as in modern humans. This study reassesses the number of sacral vertebrae in Lucy by reexamining the distal end of A.L.288‐1an in the context of a comparative sample of modern human sacra and Co1 vertebrae, and the sacrum of A. sediba (MH2). Results demonstrate that, similar to S5 in modern humans and A. sediba, the last vertebra in A.L. 288‐1an exhibits inferiorly‐projecting (right side) cornua and a kidney‐shaped inferior body articular surface. This morphology is inconsistent with that of fused or isolated Co1 vertebrae in humans, which either lack cornua or possess only superiorly‐projecting cornua, and have more circularly‐shaped inferior body articular surfaces. The level at which the hiatus' apex is located is also more compatible with typical five‐element modern human sacra and A. sediba than if only four sacral vertebrae are present. Our observations suggest that A.L. 288‐1 possessed five sacral vertebrae as in modern humans; thus, sacral number in “Lucy” does not indicate a directional change in vertebral count that can provide information on the PLCA ancestral condition. Am J Phys Anthropol 156:295–303, 2015. © 2014 Wiley Periodicals, Inc.     

Description of a New Freshwater Ciliate Epistylis wuhanensis n. sp. (Ciliophora,Peritrichia) from China,with a Focus on Phylogenetic Relationships within Family Epistylididae

Two populations of Epistylis wuhanensis n. sp., a new freshwater peritrich ciliate, were isolated from different freshwater ponds located in Hubei, China. Their morphological characteristics were investigated using live observation, protargol impregnation, and scanning electron microscopy (SEM). Specimens from the two populations showed identical arrangement of the infraciliature and identical small subunit ribosomal RNA (SSU rRNA) gene and ITS1‐5.8S‐ITS2 sequences. The zooids present bell‐shaped and 90–175 × 27–54 μm in vivo. Macronucleus is variable in shape and located in the middle of cell. Pellicle is usually smooth with 139–154 and 97–105 striations above and below the trochal band, respectively. SSU rRNA gene and ITS1‐5.8S‐ITS2 sequences of E. wuhanensis n. sp. did not match any available sequences in GenBank. Phylogenetically, E. wuhanensis n. sp. clusters with the other Epistylis within the family Epistylididae, but is distinct from the major clades of Epistylis. Above all, the morphological characteristics and molecular analyses support that the present Epistylis is a new species. Expanded phylogenetic analyses of sessilids based on both SSU rRNA gene sequences and ITS1‐5.8S‐ITS2 sequences reveal that the genus Epistylis consists of Epistylis morphospecies and taxonomic revision of the genus is needed.     

Beyond the “Code”: A Guide to the Description and Documentation of Biodiversity in Ciliated Protists (Alveolata,Ciliophora)

Recent advances in molecular technology have revolutionized research on all aspects of the biology of organisms, including ciliates, and created unprecedented opportunities for pursuing a more integrative approach to investigations of biodiversity. However, this goal is complicated by large gaps and inconsistencies that still exist in the foundation of basic information about biodiversity of ciliates. The present paper reviews issues relating to the taxonomy of ciliates and presents specific recommendations for best practice in the observation and documentation of their biodiversity. This effort stems from a workshop that explored ways to implement six Grand Challenges proposed by the International Research Coordination Network for Biodiversity of Ciliates (IRCN‐BC). As part of its commitment to strengthening the knowledge base that supports research on biodiversity of ciliates, the IRCN‐BC proposes to populate The Ciliate Guide, an online database, with biodiversity‐related data and metadata to create a resource that will facilitate accurate taxonomic identifications and promote sharing of data.     

The pronghorn (Antilocapra americana): A review as a model for development of a “Species Management Plan” format,Part I

A format is suggested for a “Species Management Plan”; the model for this presentation is the pronghorn (Antilocapra americana). By using the Species Management Plan format, the captive maintenance of pronghorn is analyzed in relation to habitat and microhabitat needs, behavioral requirements, and nutritional needs. A strategy for captive maintenance of pronghorn in relatively wet climates is presented. It is suggested that development of a Species Management Plan is necessary before any new species is acquired for captive maintenance and reproduction.     

REMARKABLE CONSERVATION OF INTERNALLY TRANSCRIBED SPACER SEQUENCES OF ARTHROSPIRA (“SPIRULINA” ) (CYANOPHYCEAE,CYANOBACTERIA) STRAINS FROM FOUR CONTINENTS AND OF RECENT AND 30‐YEAR‐OLD DRIED SAMPLES FROM AFRICA1

The internally transcribed spacer (ITS) sequences of 21 Arthrospira clonal strains from four continents and assigned to four different species (A. platensis, A. maxima, A. fusiformis, A. indica) in the culture collections were determined. Two main clusters, I and II, were differentiated by 49 positions out of 475 nt or 477 nt, respectively. Each cluster was further subdivided into two subclusters. Subclusters I.A and I.B were separated by two substitutions, whereas subclusters II.A and II.B were distinguished by four substitutions. After direct sequencing of the PCR products, three dried samples from Chad aged between 3 months and 35 years yielded a sequence belonging to subcluster I.A, as did a recent commercial product. The strains grown in production plants belonged to the same (sub)clusters as strains from culture collections, mainly I.A and II. PCR primers specific for each cluster and subcluster were designed and tested with crude cell lysates of Arthrospira strains. One dried sample (“dihé” 1) and a herbarium sample from Lake Sonachi (Kenya) only contained I.A sequences, whereas the commercial product was a mixture of the four genotypes and the other two dried samples contained minor polymorphisms characteristic of different clusters. Five clonal Arthrospira strains, thought to be duplicates, showed the simultaneous presence of the two forms of the four diagnostic positions that distinguish subclusters genotype II.A and genotype II.B. This is likely to be caused by multiple copies of the rDNA operon, in a intermediate stage of homogenization between subcluster II.A and subcluster II.B. The high conservation of ITS sequences is in contrast with the assignment to four different species, the great morphological variability of the strains, and their wide geographic distribution.     

Systematic implications of the sesquiterpene lactones in the “strumarium” morphological complex (Xanthium strumarium, Asteraceae) of Europe, Asia and Africa

In most populations of the “strumarium” morphological complex of Xanthium strumarium L. (sensu lato) in northern Europe and in India, a new compound, xanthinosin, is the only detectable sesquiterpene lactone. In populations of this morphological complex in Portugal and Egypt as well as in eastern Asia, USSR, Korea, Hong Kong and Taiwan, xanthinin and xanthatin occur as major constituents along with xanthinosin. Experimental F, hybrids between pistillate Indian plants which contained only xanthinosin and staminate plants from Hong Kong which contained a mixture of xanthinin, xanthatin and xanthinosin produced a mixture of compounds in which the percentage of xanthinin increased relative to its percentage in the Hong Kong parent. The sesquiterpenoid data suggest that the various taxa in the “strumarium” morphological complex can be divided into three groups: (a) X. strumarium (sensu stricto) and X. indicum König, containing primarily or exclusively xanthinosin; (b) X. sibiricum Patrin and X. brasilicum Vell., with xanthinin and xanthinosin predominating; and (c) X. inaequilaterum DC., with almost equal proportions of xanthinin, xanthatin and xanthinosin. Two other taxa of the complex. X. japonicum Widd. and X. abyssinicum Wallr., were not available for inclusion in the present study.